"Despite this, the system is functioning. People should remain calm. We're doing everything we can with all the forces we have. Any information we will share immediately," she said.

In the 2 1/2 hours following the 90-second quake, the U.S. Geological Survey reported 11 aftershocks, five of them measuring 6.0 or above.

Bachelet urged people to avoid traveling, since traffic lights are down, to avoid causing more fatalities.

In the capital, Santiago airport was shut down and will remain closed for at least the next 24 hours, airport director Eduardo del Canto said. The passenger terminal has suffered major damage, he told Chilean television in a telephone interview. TV images show smashed windows, partially collapsed ceilings and pedestrian walkways destroyed.

Chilean television showed images of destroyed buildings and damaged cars, with rubble-strewn streets. Dozens of people were seen roaming through the streets, including some wheeling suitcases behind them. There was a fire burning in one street with people sitting nearby trying to keep warm.

The quake hit 200 miles (325 kilometers) southwest of Santiago, at a depth of 22 miles (35 kilometers) at 3:34 a.m. (0634 GMT; 1:34 a.m. EST), the U.S. Geological Survey reported.

The epicenter was just 70 miles (115 kilometers) from Concepcion, Chile's second-largest city, where more than 200,000 people live along the Bio Bio river, and 60 miles from the ski town of Chillan, a gateway to Andean ski resorts that was destroyed in a 1939 earthquake.

Marco Vidal, a program director for Grand Circle Travel traveling with a group of 34 Americans, was on the 19th floor of the Crown Plaza Santiago hotel when the quake struck.

"All the things start to fall. The lamps, everything, was going on the floor. And it was moving like from south to north, oscillated. I felt terrified," he said.

Cynthia Iocono, from Linwood, Pennsylvania, said she first thought the quake was a train.

"But then I thought, oh, there's no train here. And then the lamps flew off the dresser and my TV flew off onto the floor and crashed."

"It was scary, but there really wasn't any panic. Everybody kind of stayed orderly and looked after one another," Iocono said.

In Santiago, modern buildings are built to withstand earthquakes, but many older ones were heavily damaged, including the Nuestra Senora de la Providencia church, whose bell tower collapsed. An apartment building's two-level parking lot also flattened onto the ground floor, smashing about 50 cars whose alarms and horns rang incessantly. A bridge just outside the capital also collapsed, and at least one car flipped upside down.

In the coastal city of Vina del Mar, the earthquake struck just as people were leaving a disco, Julio Alvarez told Radio Cooperativa in Santiago. "It was very bad, people were screaming, some people were running, others appeared paralyzed. I was one of them."

Bachelet said she was declaring a "state of catastrophe" in three central regions of the country, and that while emergency responders were waiting for first light to get details, it was evident that damage was extensive.

She said Chile has not asked for assistance from other countries.

Several hospitals have been evacuated due to earthquake damage, she said, and communications with the city of Concepcion remained down. She planned to tour the effected region as quickly as possible to get a better idea of the damage.

The Pacific Tsunami Warning Center called for "urgent action to protect lives and property" in Hawaii, which is among 53 nations and territories subject to tsunami warnings.

A huge wave reached a populated area in the Robinson Crusoe Islands, 410 miles (660 kilometers) off the Chilean coast, Bachelet said. There were no immediate reports of major damage there, she added.

"Sea level readings indicate a tsunami was generated. It may have been destructive along coasts near the earthquake epicenter and could also be a threat to more distant coasts," the warning center said. It did not expect a tsunami along the west of the U.S. or Canada but was continuing to monitor the situation.

The largest earthquake ever recorded struck the same area of Chile on May 22, 1960. The magnitude-9.5 quake killed 1,655 people and left 2 million homeless. The tsunami that it caused killed people in Hawaii, Japan and the Philippines and caused damage to the west coast of the United States.